Purchased a bad IMEI iphone., seriously confused?

Hi, so I purchased an iPhone 5s. Later on I checked the IMEI just in case to see if it was bad. Just my luck it comes up blacklisted. So far as far as I've read if you have a blacklisted phone it won't work at all. So I put my SIM card into this phone and it connects and works perfectly fine. Used it all day actually and didn't have one problem. Can anyone tell me why? I thought if a phone had a bad IMEI, then the phone would never connect to the service, but it did. I'm very curious.

Basically, if the IMEI is blacklisted (and you didn't read it wrong), the phone is most likely stolen, so you're now in possession of stolen goods. Should have checked before you bought it.

As for blacklisting the IMEI - in theory, sometimes. In practice, though, most providers simply don't care. If I wanted to be cynical, I could come to the conclusion that each phone that had been stolen means a new phone for them to sell as a replacement, so they're not that much interested in bringing down phone theft…